In an electrical power distribution system, a transformer is commonly used to step down a higher voltage to a lower voltage more suitable for supplying customer electrical loads. A transformer typically includes an output conductor in the form of a threaded stud that, in turn, is connected to a plurality of individual electrical conductors by a transformer stud connector. A transformer stud connector may be connected to the threaded transformer stud using either a screwed on connection or a more convenient slip-fit connection.
A typical screwed on connector includes a threaded opening extending into the connector body. A lock nut is typically used to lock the connector and stud together. The connector body also typically has a plurality of conductor receiving passageways therein, and corresponding fastener receiving passageways intersecting the conductor receiving passageways. Accordingly, a conductor can be inserted into the conductor receiving passageway and secured therein by tightening a corresponding fastener.
A transformer connector using a threaded connection is also disclosed in U.S. Pat. No. 4,382,651 to Klosin et al. The connector includes a body having a threaded transformer stud receiving passageway extending longitudinally therein for receiving the threaded transformer stud. The transformer stud connector is screwed onto the threaded stud and locked into place with the tapered end of a conical screw that bears against the chamfer of the threaded stud.
Another transformer stud connector is disclosed in U.S. Design Pat. No. 309,664 to McGrane. The connector includes two generally rectangular body portions joined together in offset relation. A different sized stud receiving passageway is formed into each of the body portions.
A slip-fit transformer connector is illustrated in U.S. Pat. No. 4,214,806 to Kraft. The Kraft transformer connector includes a connector body, a transformer stud receiving passageway extending into the end of the body, and a stud fastener for fastening the transformer stud within the stud receiving passageway. A U-shaped groove is provided along the bottom of the transformer stud receiving passageway. The U-shaped groove, in combination with the fastener, provides three areas of contact with the transformer stud. This transformer stud connector, however, accommodates only one transformer stud size.
Another slip-fit transformer connector is illustrated in U.S. Pat. No. 5,690,516 to Fillinger. This transformer connector includes a transformer stud receiving passageway defined by a first smooth passageway and a smaller threaded passageway below the first smooth passageway. The threaded stud is slipped into the transformer stud receiving passageway and locked into place by a stud fastener. The shape and threads on the bottom exactly match the threads on the threaded stud. Accordingly, this connector is adapted to receive only one transformer stud size.
Another stud connector is offered by CMC/ESP Utility Products of Hamilton, Ohio under the designation TYPE SHB (quick Disconnect) that includes a stud receiving passageway having different sized portions to accommodate different sized transformer study. More particularly, the stud receiving passageway includes a small threaded bottom, a larger threaded landing above the threaded bottom, and an enlarged smooth upper portion. The threaded portions are sized to exactly accommodate the respective threaded studs. Moreover, the arrangement of the bottom threaded portion may permit undesired rocking or movement of the stud.